Adding second battery

Cannoy · 06-17-2019, 05:07 PM

i’m currently looking at a 2007 328i and i found out that the batteries have to be registered. i plan on adding a 3500 watt amp and would like to add a second battery, how does battery registering work if you have two batteries?

Dr.Angel1017 · 02-21-2020, 03:07 PM

Register your main battery if it was upgraded and just run the other battery parallel, make sure to fuse the wire off the battery.

mweisdorfer · 02-22-2020, 01:56 PM

Quote:

Originally Posted by Cannoy

i'm currently looking at a 2007 328i and i found out that the batteries have to be registered. i plan on adding a 3500 watt amp and would like to add a second battery, how does battery registering work if you have two batteries?

Why do you need that much power? 3500 watts?! You really only need 1/2 that for a small car like the e90.

100 watts per channel x 8 is almost overkill. I have 75 watts per channel and I can crank it up pretty loud!

Ali-E90 · 02-23-2020, 02:39 PM

Quote:

Originally Posted by mweisdorfer

Quote:

Originally Posted by Cannoy

i'm currently looking at a 2007 328i and i found out that the batteries have to be registered. i plan on adding a 3500 watt amp and would like to add a second battery, how does battery registering work if you have two batteries?

Why do you need that much power? 3500 watts?! You really only need 1/2 that for a small car like the e90.

100 watts per channel x 8 is almost overkill. I have 75 watts per channel and I can crank it up pretty loud!

Not everyone is satisfied with just "personal" listening levels, it's not that uncommon to go 4K+ watts nowadays, amps are relatively cheap, and bragging rights are on the line! Lol

Ali-E90 · 02-23-2020, 02:40 PM

Also, 75-100w rms may be ok for mids, even midbass if not going too loud... but any dedicated sub you'd want a minimum of 300w rms anyway.

mweisdorfer · 02-23-2020, 06:13 PM

Quote:

Originally Posted by Ali-323i

Also, 75-100w rms may be ok for mids, even midbass if not going too loud... but any dedicated sub you'd want a minimum of 300w rms anyway.

I have a dedicated sub at 300w rms

ewicky · 02-28-2020, 05:36 PM

How are you planning on isolating and/or charging the second battery? Have you looked at using capacitors or super capacitors instead? What is the standby consumption of the amp? IBS will flare up if more than a few mA. Do you plan on grounding the amp to the chassis or the battery?

06-17-2019, 05:07 PM	#1
Cannoy Registered 0 Rep 2 Posts Drives: BMW 328i Join Date: Jun 2019 Location: Kentucky iTrader: (0)	Adding second battery i’m currently looking at a 2007 328i and i found out that the batteries have to be registered. i plan on adding a 3500 watt amp and would like to add a second battery, how does battery registering work if you have two batteries?
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02-21-2020, 03:07 PM	#2
Dr.Angel1017 New Member 0 Rep 5 Posts Drives: Bmw 328xi 2008 Join Date: Feb 2020 Location: California iTrader: (0)	Register your main battery if it was upgraded and just run the other battery parallel, make sure to fuse the wire off the battery.
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02-23-2020, 02:40 PM	#5
Ali-E90 Colonel 379 Rep 2,365 Posts Drives: 2007 E90 323i (Cdn) Join Date: May 2013 Location: Toronto, Canada iTrader: (3) Garage List 2008 BMW M3 [8.00] 2007 BMW 323i [8.50]	Also, 75-100w rms may be ok for mids, even midbass if not going too loud... but any dedicated sub you'd want a minimum of 300w rms anyway. __________________ Check out my Mod Thread Here
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02-28-2020, 05:36 PM	#7
ewicky Lieutenant 204 Rep 525 Posts Drives: '07 335xi 4D AT Join Date: Jan 2017 Location: Seattle, WA iTrader: (0)	How are you planning on isolating and/or charging the second battery? Have you looked at using capacitors or super capacitors instead? What is the standby consumption of the amp? IBS will flare up if more than a few mA. Do you plan on grounding the amp to the chassis or the battery?
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